1. Field of the Invention
The present invention generally relates to a semiconductor device, a method of manufacturing the semiconductor device, and a method of manufacturing a lead frame, and more particularly, to a semiconductor device and its manufacturing method in which a semiconductor device and leads are sealed with plastic, and a method of manufacturing a lead frame which is used in the semiconductor device.
Recently, as an electronic apparatus containing semiconductor devices is miniaturized, integration and high-density fabrication of the semiconductor devices are performed.
On the other hand, reliability of both the electronic apparatus and the semiconductor devices needs to be improved. Furthermore, semiconductor devices capable of reducing a product cost are also desired.
2. Description of the Related Art
Recently, as a method of fabricating semiconductor devices at high density, a fabrication structure of a flip-chip method is well-known, and is widely used in a multi-chip module (MCM). In the flip-chip-type fabrication used in the MCM, after bumps are formed on electrode pads of an unsealed semiconductor chip (a bare chip), the bare chip is bonded face down to electrode parts of a mother board.
When the fabrication structure of the flip-chip method is used, the semiconductor devices may be arranged on the mother board at high density. Since the semiconductor device is electrically connected to the mother board by using the bumps directly formed on the bare chip, electrical characteristics may be improved.
However, there is a problem in that an unsealed bare chip has disadvantages in heat resistance, mechanical strength, and wet proofing.
Further, since the bumps are directly formed on the electrode pads formed in the bare chip to form external connection ports, a layout of the electrode pads formed in the bare chip becomes directly a layout of the external connection ports (bumps).
Typically, the layout of the electrode pads of the semiconductor device chip is different for each semiconductor-device manufacturing company. Therefore, even if the semiconductor devices have the same function, a user needs to design line patterns of the mother board adaptable to a variety of semiconductor devices (a variety of manufacturing companies). In this way, in a conventional fabrication structure using the bare chip, since the layout of the external connection ports of the semiconductor device is not standardized, the semiconductor device may not be matched to the mother board. There is thus a problem that a work load for the user increases.
To resolve the above problem, it is considered that standardization is carried out by arranging a large number of lines on a surface of the chip. However, in this configuration, many high-precision processes are required for arranging the large number of lines. The many high-precision processes increase a product cost and degrade a manufacturing efficiency.